class MultiArray(object):
# Creates a multi-dimentional array.
def __init__(self, *dimensions):
assert len(dimensions) > 1, 'The array must have 2 or more dimensions.'
# The variable argument tuple contaims the dim sizes.
self._dims = dimensions
# Compute the total number of elements in the array.
size = 1
for d in dimensions:
assert d > 0, 'Demensions must be > 0.'
size *= d
# Create the 1-D array to store the elements.
self._elements = Array(size)
# Create a 1-D array to store the equation factors.
self._factors = Array(len(dimensions))
self._computeFactors()
# Returns the number of dimensions in the array.
def numDims(self):
return len(self._dims)
# Returns the length of the given dimention.
def length(self, dim):
assert dim >=1 and dim <= len(self._dims), \
'Dimention component out of range.'
return self._dims[dim - 1]
# Clears the array by setting all elements to the given value.
def clear(self, value):
self._elements.clear(value)
# Returns the contents of element(i_1, i_2, ..., i_n).
def __getitem__(self, ndxTuple):
assert len(
ndxTuple) == self.numDims(), 'Invalid # of array subscripts.'
index = self._computeIndex(ndxTuple)
assert index is not None, 'Array subscript out of range.'
return self._elements[index]
# Sets the contents of element(i_1, i_2, ..., i_n).
def __setitem__(self, ndxTuple, value):
assert len(
ndxTuple) == self.numDims(), 'Invalid # of array subscripts.'
index = self._computeIndex(ndxTuple)
assert index is not None, 'Array subscript out of range.'
self._elements[index] = value
# Computes the 1-D array offset for element (i_1, i_2, ..., i_n)
# using the equation i_1 * f_1 + i_2 * f_2 + ... + i_n * f_n
def _computeIndex(self, idx):
offset = 0
for j in range(len(idx)):
# Make sure the imdex components are within the legal range.
if idx[j] < 0 or idx[j] >= self._dims[j]:
return None
else: # Sum the product of i_j * f_j.
offset += idx[j] * self._factors[j]
return offset
# Computes the factor values used in the index equation.
def _computeFactors(self):
for j in range(len(self._factors)):
self._factors[j] = 1
if j != len(self._factors) - 1:
for i in range(j + 1, len(self._factors)):
self._factors[j] *= self._dims[i]
class MultiArray(object): # Creates a multi-dimentional array. def __init__(self, *dimensions): assert len(dimensions) > 1, 'The array must have 2 or more dimensions.' # The variable argument tuple contaims the dim sizes. self._dims = dimensions # Compute the total number of elements in the array. size = 1 for d in dimensions: assert d > 0, 'Demensions must be > 0.' size *= d # Create the 1-D array to store the elements. self._elements = Array(size) # Create a 1-D array to store the equation factors. self._factors = Array(len(dimensions)) self._computeFactors() # Returns the number of dimensions in the array. def numDims(self): return len(self._dims) # Returns the length of the given dimention. def length(self, dim): assert dim >=1 and dim <= len(self._dims), \ 'Dimention component out of range.' return self._dims[dim - 1] # Clears the array by setting all elements to the given value. def clear(self, value): self._elements.clear(value) # Returns the contents of element(i_1, i_2, ..., i_n). def __getitem__(self, ndxTuple): assert len(ndxTuple) == self.numDims(), 'Invalid # of array subscripts.' index = self._computeIndex(ndxTuple) assert index is not None, 'Array subscript out of range.' return self._elements[index] # Sets the contents of element(i_1, i_2, ..., i_n). def __setitem__(self, ndxTuple, value): assert len(ndxTuple) == self.numDims(), 'Invalid # of array subscripts.' index = self._computeIndex(ndxTuple) assert index is not None, 'Array subscript out of range.' self._elements[index] = value # Computes the 1-D array offset for element (i_1, i_2, ..., i_n) # using the equation i_1 * f_1 + i_2 * f_2 + ... + i_n * f_n def _computeIndex(self, idx): offset = 0 for j in range(len(idx)): # Make sure the imdex components are within the legal range. if idx[j] < 0 or idx[j] >= self._dims[j]: return None else: # Sum the product of i_j * f_j. offset += idx[j] * self._factors[j] return offset # Computes the factor values used in the index equation. def _computeFactors(self): for j in range(len(self._factors)): self._factors[j] = 1 if j != len(self._factors) - 1: for i in range(j + 1, len(self._factors)): self._factors[j] *= self._dims[i]
# Count the number of occurrences of each letter in a text file.
from my_own_array import Array
# Create an array for the counters and initialize each element to 0.
theCounters = Array(127)
theCounters.clear(0)
# Open the text file for reading and extract each line from the file
# and iterate over each character in the line.
with open('atextfile.txt', 'r') as theFile:
content = theFile.read()
for letter in content:
code = ord(letter)
theCounters[code] += 1
# Print the result. The uppercase letters have ASCII values in the
# range 65...90 and the lowercase letters are in the range 97...122.
for i in range(26):
print('%c - %4d %c - %4d' % \
(chr(65+i), theCounters[65+i], chr(97+i), theCounters[97+i]))